BMW N54 Problems to Expect – Reliability Report

So, you’re looking at a BMW with the N54 engine but you’ve heard that this may not be the most reliable engine in the BMW line up. Hi guys and welcome back to the SimpleCarGuy channel. Today, we will talk about the history, common problems, issues solved over time, how reliable the engine is 15 years later as well as my personal experience.

The reason I’m making this video is because I owned a BMW 335i e92 with the N54 engine for about 4 years from 2013 to 2017 and I wanted to catch myself up and see how the reliability has been since I sold my car! This is also part of a small series where I’m looking into engines I own or have owned and creating reliability reports like this video. BMW N55 video is coming up soon, so subscribe to see it and hit that like button to support the channel!

History/Background:

BMW N54 is one of the best straight six engines every made by BMW for a few very good reasons. Not only was it the first mass produced BMW turbocharged engine, but it also came with a forged crankshaft and connecting rods leaving HUGE tuning potential. Even though the stock engine made 302 HP, it’s not very difficult to get it up to 500hp or even much, much more. So, how can this reward winning engine [show which awards] have issues? Well, while the actual engine has had some amazing innovations and engineering, a lot of the accessories and  auxiliary components are not as well designed. Of course, when looking at a used BMW with the N54 engine, it doesn’t help that a lot of them have been tuned and driven hard! [HUGE tuning potential and people love it, but also abuse it] So, let’s take a look at some common problems you can expect on a BMW N54 engine

Common Issues:

Even though there were 3 different power figures for this engine, mechanically its basically the same engine. I’ll go over the difference between the standard N54B30 and the N54B30TO that was used in the 1 Series M Coupe and Z4 sDrive35is.

N54B30

  1. HPFP

Let’s start with the stand N54B30 engine. The biggest and most common issue that has haunted the BMW N54 engine since the start is the HPFP going bad and preventing the engine from starting, sometimes stuttering, misfiring or running well in general. It was such a big issue that BMW has extended the warranty on these to 10 years and 120,000 miles in the United States. The good part here is that most of the cars have already had the pump replaced with a revised version while under warranty.

  • Water Pump

Another big common problem on the N54 engine is the electric water pump that uses some plastic parts. These fail unexpectedly and usually at the worst time! I’ve had 2 OEM water pumps fail on me when I had the car. I got the yellow triangle saying that the engine is running hot and within 2 minutes a red triangle with a message saying to drive moderately and to shut off the engine as it has overheating. Unlike the HPFP, there is no extended warranty or anything like that and unfortunately, the pump is very difficult to get to. I paid around a $1000 each time it failed in Chicago. The pump is about $400 and labor is at least that much again.

  • Fuel Injectors leaking, Ignition Coils

These engines also suffer from leaky injectors. BMW N54 uses direct injection and these must be very precise for the engine to run correctly. Unfortunately, when they start leaking which  can cause many different problems including hard to start engine once warmed up, rough idle and misfires as well as terrible fuel economy among other issues. Of course, some of these symptoms can be caused by a bad spark plug or coil and I would definitely recommend replacing those before touching the injectors as each injector is about $250.

  • Turbochargers/wastegate rattle – people upgrade them for more power

Next issue that’s common on many BMW engines including the N54 is the wastegate rattle. Early on, this isn’t a huge issue as it mostly just makes a rattling noise on start up, it gets worse and worse over time. Eventually, the wastegate flapper starts leaking boost and causing performance issues. If not taken care of at this stage, the ECU will try to compensate for the lack of boost potentially overheating and destroying the turbocharger and maybe even the engine if metal gets into the intake. In addition to the wastegate rattle issue, turbo seals can fail and cause smoke out of the exhaust. These issues are more common on tuned or hard driven cars. Small piece of advice here is to not punch it hard until the engine is fully warmed up and to let the engine idle for a little while after driving hard before shutting off the car. [explain why let it idle][Aftermarket upgrades are very popular.]

  • Leaks become more common once getting closer to 100k

If you have watched my BMW N20 engine video [link it], this will sound very familiar. There are a few oil leaks to watch out for and the most common one is the valve cover oil leak. Usually, the plastic valve cover will crack and start leaking. Sometimes the gasket goes bad as well and the entire cover should be replaced. It’s important to get this done quickly as it would be leaking on the exhaust manifold, turbos and the O2 sensors. The oil filter housing gasket is also prone to leaking and should be replaced ASAP as it will leak oil onto the serpentine belt and can cause all kinds of problems. Oil pan leaks are less common, but possible.

  • Chargepipe

The next common issue on these engines is the chargepipe that cracks over time. BMW used a plastic pipe between the intercooler and the intake manifold which runs under boost a lot of times and of course becomes brittle and eventually fails. I’ve had this fail on my N55 [n55] engine as it uses the same design and replaced it with an aftermarket one that works much better. This is an easy and inexpensive fix to a common problem.

  • Minor items:

There are of course many other little issues with these engines that you may need to take care of over time, such as the starters going bad out of no where [link N20 video] or VANOS solenoids causing loss of power, engine hesitation, rough idle and decreased fuel economy. I have actually made a video on how to test and clean these if you’re interested and they are a decently simple DIY. Carbon build up is another issue that shows up on many lists, but that’s common on most direct injected engine and not BMW or this engine specific.

N54B30TO

As I mentioned earlier, N54B30TO was the more powerful version of the N54 engine making 335HP, but this was achieved mostly by adding a performance power kit tune and some supporting cooling hardware. [list: upgraded fan, radiator hoses, secondary radiator, oil cooler]. So, the engine itself was the same but with just a little more boost. This also means that all problems we have discussed so far are also present on this version of the engine as well.

Best and Worst Years:

Now 15 years after it has been released and after so many problems, should you even be looking at buying one? Luckily, this engine has had somewhat of a cult following lately and is becoming sought after in the tuner’s world. This also means that most people are trying to preserve it and maintain it properly. Additionally, issues like the HPFP and injectors have been resolved from the dealer and mostly done under warranty. Most other issues have been figured out in the aftermarket world with the upgraded turbochargers to get rid of the wastergate rattle and metal chargepipes to prevent boost leaks. One word of advice, avoid getting an already tuned engine if you plan on dailying your ride. [notes on why not]

Personal Experience:

A quick note on my personal experience with the engine. Over the period of 4 years and about 55,000 miles, I had to replace the spark plugs, ignition coils and 2 water pumps and nothing else. In every video I’ve made about the BMW engines I’ve owned, people tell me I just got lucky and that may be true, but it doesn’t hurt to properly take care of these engines as well.

Conclusion:

In conclusion, remember that this is an aging BMW motor that was packed with top-of-the-line technology and most likely driven hard by the last owners, so be ready to spend a little bit of money on maintaining it properly. It’s a wonderful, powerful and still one of the more reliable engines made by BMW with lots of aftermarket support and capability to produce tremendous power! Check out my BMW N20 and N63 engine reliability reports and stay tunes for the N55 video as well. Thank you so much for watching and I’ll see you in the next one!

BMW N55 Engine Rebuild Project Part 5 – Timing Chain and Oil Pump Replacement

Hey Guys and Welcome back to the SimpleCarGuy channel. In this video, we will have some fun installing the oil pump, oil pick up tube, the timing chain and timing the engine. I liked doing the timing chains so much that I did it twice. More on that later!

If you are new here, well, I have been rebuilding my BMW N55 engine for the past few weeks and it’s been a great learning experience. I have replaced the main bearings, crankshaft, sealed the bed plate, installed new rod bearings and a new head gasket. The last huge item on the list is the timing chain, which is today’s video.

While I’m doing this with the engine out, it is possible to do a timing chain job without having to remove the engine from the car. As in previous videos, I won’t be showing those steps, but I’ll do a quick overview on how to get where we are. I recommend you watch my previous videos where I show a lot more detail on disassembly.

HOW TO GET TO THIS POINT:

So, the quick overview. Here we go.

Step 1: Unplug the battery and drain the oil from the engine. Remove air filter housing or clean air pipe running over the valve cover depending on the car and undo the gas pressure lines.

Step 2: Remove the underbody protection, intake silencer housing, fan cowl and the serpentine belt that runs the accessories. With that access, you can now remove the vibration damper and the front crankshaft seal. If the belt tensioner is in the way, you may need to remove it as well.

Step 3: Remove the valve or also known as the cylinder head cover by unplugging the vacuum lines, wiring from the injectors and anything else that’s in the way. If you will be reusing the valve cover, make sure you undo the bolts in the correct order (show here) and remove it from the cylinder head.

If you aren’t replacing the oil pump or oil pump chain and sprocket, no further disassembly is required. Otherwise, you will have to remove the front axle differential, remove the power steering pump and remove the bearing support to be able to remove the oil sump and have access to those parts.

Before you can remove the timing chain or the oil pump components, you have to rotate the engine into the TDC (Top Dead Center) position using the main bolt. You know it’s in the correct position when cylinder number 1 is at the very top. Now we can install the timing tool onto the camshaft to make sure they do not move while we remove the central bolts on the intake and exhaust camshaft adjusters. You should have no issues unbolting these. Then remove the chain tensioner as well which will give your chain some slack and allow you to remove the camshaft adjusters by hand.

Next, the main bolt must be loosened and taken out. This is a tough one. With the engine out, it took an 8 foot pipe to get it done, but I have also done it in with the engine in the car on my N20 timing chain job and it was a little easier. Whichever way you go about this, make sure the socket is very secure on the bolt and doesn’t slip and spray some WD-40 or whatever else you have if it’s a bit rusty.

With the main bolt out, there are only a few things holding the timing chain and timing chain guide in place. The 2 bearing journals that are hiding behind the screw plugs, the crankshaft hub, two little screws at the top by the camshaft adjusters and of course the camshaft adjusters themselves. With those removed, hold the timing chain and guides with one hand and remove the hub with the other making sure not to drop the sprocket. I recommend keeping the chain tight to avoid this and just pull it up as soon as the hub has cleared it.

Now that everything out of the way, we can finally get to fun parts! Since I’m rebuilding the engine, I’m reinstalling the oil pump using new bolts. The install is very simple, but to be safe I do a mock up with old bolts while I’m working on getting the chain assembly in. Just in case I have to move it or something isn’t lining up properly. If I used new bolts and have to loosen them, I’d have to get new bolts again. The 3 bolts at the top are torqued to 10 Nm and then 180 degrees angle of rotation for the longer bolt and 90 degrees for the shorter bolts.

We are almost done with this job and as you can see it does take some time and effort to get there, no wonder a shop would charge you a couple thousand bucks for this! Anyway, to install the new chain and tensioner, make sure it’s all assembled correctly and the sprocket pointing the right way. Then it can all be lowered into the engine, lining up the sprocket with the crankshaft hub and locking it in place with a new main bolt. You don’t want to tighten it to spec just yet. First, reinstall the 2 bearing journals and the 2 little screws at the top to hold everything in place. Torquing all to spec, of course.  Now the main bolt can be torqued to 100 Nm and additional 270-degree rotation. I recommend having someone help you out with this one, it felt a little sketchy as I was doing it.

With the main bolt locking everything in place, it’s time to install the intake and exhaust camshaft adjusters back in with the chain around them. Should be pretty easy since the chain tensioner is not yet installed. Of course, you have to make sure that the intake adjuster goes on the right side and the exhaust on the left, you cannot mix these up! While you are pulling the chain over the exhaust adjuster, make sure it is sitting on the guide rail and not anywhere else. With everything looking good, we can install the pretensioning tool instead of the chain tensioner and torque it to 0.6 Nm and torque the central bolts to 20 Nm with 180-degree rotation after. The very last step before testing is installing the chain tensioner and torquing it to 55 Nm.

Once everything looks good, we can remove all special tool and rotate the engine a couple of times making sure everything sounds good and recheck the timing. If everything still lines up and the timing tool fits as it did before the engine is timed and ready for its new crankshaft seal and re-assembly. A video on front crankshaft seal is coming out soon!

Now, remember how I said I had to do this job twice? Well, after I rotated the engine a few times, it made this clicking sound from the camshaft adjuster which I wasn’t very sure about. So, I posted a short clip to check with others and see if it’s normal. I learned that indeed, it is normal and it will go away as soon as oil pressure is built up and circulating, but I also learned that I was making a mistake. Initially when I looked at the timing components, they looked fine to me so I reused them.. but after many, many convincing arguments from strangers, I have decided to replace it all with brand new stuff, including the chain tensioner. Anyway, thanks for watching, check out the links in the description for parts needed, leave a comment down below and I’ll see you in the next one.